What are AI coding agents?

AI coding agents read your code, run commands and make changes from plain-English instructions.

📖 Key ideas

Examples: Claude Code (Anthropic), Codex (OpenAI), GitHub Copilot agent mode, Cursor.
They work in the terminal, the IDE, or the cloud on a copy of your repo.
Unlike autocomplete, an agent plans steps, edits several files and runs tests.
You stay responsible for the code: review every change.
They speed up boilerplate, debugging, refactors and learning a new codebase.

💡 Real-life example: Like a capable junior developer who works very fast: great help, but a senior still reviews their pull request.

Coding agentAI that plans and edits code using tools

AutocompleteSuggests the next few lines only

Claude CodeAnthropic's agentic coding tool

CodexOpenAI's coding agent